褐稻虱自然种群生命表的组建方法

本文把褐稻虱种群按其生长发育顺序划分为卵（E）、1－2龄若虫（S）、3－4龄若虫（L）和成虫（A）4个阶段，把各阶段的作因子划分为相对独立的状态（staltes)，在稻田调查中分别记录其单位面积的数量。通过换算，计算卵、1－2龄若虫和3－5龄若虫的存活率（Sg,Ss,Sl)及各作用因子相对应的存活率（S1，S2，S3，S4，S5，S6），同时通过实验种群的产卵量（FPfP），成虫逐日产卵概率（Pn)和自然种群成虫逐日存活率（AAa)组成的下代卵量概率，∑Pfl(SAa)′组成褐稻虱自然种群生命表的各个组分，如果包含成虫迁移后的居留率St,则根据生命表组分建立的种群趋势数字模型(Morris-Watt种群数学模型^[7,10,11])可扩充为：I＝SESSSLFPFP♂St∑Pfl(SAa)协′I＝S1S2S3S4S5S6FPFP♀St∑Pfl(SAa)′。     

中国幽门螺杆菌基因组多样性与种群结构分析

目的 了解中国幽门螺杆菌（Helicobacter pylori,HP）基因组特征及种群结构。方法 利用中国不同地域不同疾病分离的10株HP的基因组序列,并整合公共数据库中其他地域的HP基因组数据,通过比较基因组和生物信息学方法分析中国HP的基因组与种群结构特征。结果 中国HP核心基因为1 203个。菌株特异基因为19～32个,这些基因可能与中国HP在不同地域、不同疾病宿主中的适应性进化有关。基因组变异较大区域主要集中在编码限制修饰系统的基因和编码四型分泌系统的基因。基于核心基因组单核苷酸多态性（SNP）的种群分析确定中国菌株均属于hpEastAsia群,hspEAsia亚群,且不同地域菌株具有地域聚集性特点。在3株中国HP基因组序列中发现了前噬菌体序列,携带噬菌体组装所需的必要元件。结论 基于核心基因组SNP分析中国菌株均属于hpEastAsia群,hspEAsia亚群,且具有地域聚集性。为深入挖掘中国不同地域不同疾病相关HP的遗传特征及研究噬菌体在HP进化与致病中的作用奠定了基础。     

The ‘Hot Spot’ of Hb E [β26(B8)Glu→Lys] in Southeast Asia: β‐Globin Anomalies in the Lao Theung Population of Southern Laos

Hb E [β26(B8)Glu→Lys], is the most common abnormal hemoglobin (Hb) in Southeast Asian populations. The hitherto highest frequencies of the Hb E gene (HBB^*E) in large population samples, ～?0.3, were observed in the southern part of northeastern Thailand. The finding of even higher frequencies in a small, isolated Austroasiatic group in Northeast Thailand prompted us to examine samples of three Austroasiatic populations in southern Laos (official designation: Lao Theung), an area inhabited by numerous ethnic groups belonging to the Mon–Khmer branch. Blood samples were collected from a total of 603 adult subjects. The HBB^*E frequencies were 0.426 in the So of Khammuan Province, 0.433 in the Alak/Ngeh of Sekong Province and 0.253 in the Oy of Attapeu Province. The HBB^*E frequencies in the So and Alak/Ngeh are the highest observed in Southeast Asia in representative population samples. None of the common Southeast Asian β‐thalassemia (thal) mutations were found. The results are discussed with respect to natural selection by malaria, selection time, effects of β‐thal and the ethnic history of the population of Southeast Asia.     

Impact of Guidelines for Antihypertensive Treatment on Clinical Practice

Many Guidelines and Consensus Statements were published in 1993 and 1994. The pressure to produce these guidelines comes from clinicians faced with rapid change, from a wish to provide an independent authoritative view rather than rely on commercial promotion of particular treatments, and from governments seeking assistance with the allocation of scarce resources.

Evaluation of the impact that guidelines exert on clinical practice is notoriously difficult, but has been attempted using the self-report questionnaire, or the more reliable but expensive analysis of actual practice data, before and after publication of the guidelines.     

The potential health impacts of climate change: An overview

Climate change would have a range of impacts on human health. Health impacts would be caused by the direct effect of climatic factors on human health, such as heat stress, and possible changes in the frequency and intensity of extreme weather events such as storms, floods and droughts. Impacts on health would also be mediated by the indirect effects of climate change, such as changes in availability of food and water and the distribution of vector‐borne diseases. The majority of health impacts would be adverse and would depend greatly on the vulnerability of populations.     

Spatial spread and demographic expansion of Lyme borreliosis spirochaetes in Eurasia

The Lyme borreliosis (LB) group of spirochaetes currently comprises 18 named species that vary in their geographic distribution, host specificity and ability to cause disease in humans. In Europe three species are most abundant, Borrelia afzelii, Borrelia garinii and Borrelia valaisiana but only two of these (B. garinii and B. afzelii) are regularly found in Asia as well. A recently published study has shown that Borrelia species associated with birds, such as B. garinii, showed limited geographic structuring between European countries while, the rodent associated species, B. afzelii, showed extensive spatial structuring in Europe. Here, we use multilocus sequence analysis to show that when the wider, inter-continental, distribution is considered, there is evidence of spatial structuring even in the bird-associated species B. garinii. Furthermore, our investigations into historical LB populations provided evidence for range expansions of B. garinii and B. afzelii populations in Europe in the distant past. We propose that the expansion of B. afzelii in Europe may be linked to rodent population expansions after the last glacial maximum.     

网络规模迭加法开展人群规模估计的研究进展

网络规模迭加法是一种在社会网络理论基础上建立的间接估计人群规模的方法,由于不需要接触目标人群,在估计隐藏人群规模时得到了广泛应用。该方法也在不断发展进步中,本文从传统的网络规模迭加法及其进展及与新的调查技术结合三个方面进行综述,旨在为该方法的进一步应用提供参考。     

A benchmark dose study of prenatal exposure to di(2-ethylhexyl) phthalate and behavioral problems in children

IntroductionPrenatal exposure to di(2-ethylhexyl) phthalate (DEHP) has been reported to be associated with adverse effects on neurodevelopment that yield behavior syndromes in young children with an estimated median exposure lower than the currently recommended tolerable daily intake (TDI) and reference dose (RfD).ObjectivesOur aim was to derive the benchmark dose for prenatal exposure to DEHP for the neurodevelopmental health in children.MethodsA total of 122 mother-child pairs from the Taiwan Maternal and Infant Cohort Study were analyzed for the dose-response relationship between maternal exposure to DEHP and children's behavioral syndromes evaluated at 8 years (n = 122, 2009), 11 years (n = 96, 2012), and 14 years (n = 78, 2015) of age. We employed a multivariate regression model to assess the statistical associations between the estimated maternal average daily intake of DEHP and child's individual CBCL scores for boys and girls at each separate age, followed by a mixed model for all the children across three ages accounting for individual variations. We then employed structural equation models by combining the children's specific behavioral problem scores at different ages and obtained a simulated overall latent score in relation to maternal exposure. Based on the established dose-response relationship, we derived the benchmark dose (BMD) and the lower limit (BMDL).ResultsAssociations of maternal DEHP exposure (median 4.54$\mu g/kg\_bw/day$) with the Child Behavior Checklist (CBCL) scores were all significant, except for somatic complaints, adjusting for child's age, gender, IQ, and family income. The BMDL, given a benchmark response of 0.10 (0.05) and a background response of 0.05, was 6.01 (2.16) $\mu g/kg\_bw/day$for an integrated CBCL score.ConclusionsThe current TDI (RfD) of 50 (20) $\mu g/kg\_bw/day$ for DEHP might not protect pregnant women for their children from behavioral problems. There remains the lack of comparable toxicological data. Further investigations are needed.     

Five-year mortality trends associated with chronic pancreatitis in South Korea: A population based cohort study

BackgroundChronic pancreatitis (CP) is associated with all-cause and cancer-related mortality; however, the risk of mortality associated with alcoholic and non-alcoholic CP remains controversial. This study investigated whether CP increased the risk of 5-year all-cause and cancer-specific mortality compared to a control population.MethodsThis population-based study used data from a sample cohort of the National Health Insurance Service (NHIS) database in South Korea. CP was defined as disease code K86.0 (alcohol-induced CP) and K86.1 (other CP and non-alcoholic CP) from the tenth edition of the International Classification of Diseases.ResultsThe prevalence of chronic alcoholic pancreatitis increased from 0.01% in 2002 to 0.07% in 2015, and the prevalence of chronic non-alcoholic pancreatitis increased from 0.08% in 2002 to 0.50% in 2015. In the 2010 NHIS cohort (n = 826,909), CP was associated with an increased risk of 5-year all-cause mortality (hazard ratio [HR] = 1.25, 95% confidence interval [CI]: 1.25 to 1.66, P < 0.001). Additionally, non-alcoholic CP was associated with an increased risk of 5-year all-cause mortality (HR = 1.47, 95% CI: 1.27 to 1.71, P < 0.001); in contrast, alcohol-induced CP was not significantly associated with mortality risk (P = 0.569). Similar tendencies were observed for the 5-year cancer-related mortality risk.ConclusionsIn South Korea, the prevalence of alcoholic and non-alcoholic CP increased during 2002–2015. CP may be an independent risk factor for 5-year all-cause and cancer-related mortality. In this study, this association was more evident in patients with non-alcoholic CP.